# Addy
Allows pretty summations. Instead of writing:
(1..5).inject(0) do |memo, num|
memo + (num**num)
end
You write:
sum(1..5) do |num|
num**num
end
Personally, I would rather write the latter.
## Usage
Install the gem:
gem install addy
Then use it!
require 'addy'
class MyClass
#include it in a class or in Object to get it everywhere
include Addy
def my_awesome_adder(range)
sum(range)
end
end
When you include addy on a class that implements inject, you don't even need to pass a value to it. Instead it calls sum on your class.
require 'addy'
class MyClass < Range
include Addy
def my_awesome_adder
sum
end
end
### Calling It
You can call either sum or summation. They're aliases for the same thing.
Note: The following assumes Addy is included into Range.
When you pass a block to sum it will execute the block on the current number before adding it to the sum.
sum(1..5) {|num| num + 1} #=> 20
(1..5).sum {|num| num + 1} #=> 20
You don't have to pass a block though!
#this
sum(1..5) #=> 15
#and
(1..5).sum #=> 15
#are equivalent to
sum(1..5) {|num| num} #=> 15
#and
(1..5).sum {|num| num} #=> 15
### Input
Ranges and numeric arrays both work well.
sum(1..5) #=> 15
sum([1,2,3,4,5]) #=> 15
## Note on Patches/Pull Requests
* Fork the project.
* Make your feature addition or bug fix.
* Add tests for it. This is important so I don't break it in a
future version unintentionally.
* Commit, do not mess with rakefile, version, or history.
(if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
* Send me a pull request. Bonus points for topic branches.
## Copyright
Copyright (c) 2010 Allen Madsen. See LICENSE for details.
PS: Isn't it ridiculous how much documentation I wrote for one function?